1. Field of the Invention
The present invention relates to automotive lamp units including automotive lamps to be mounted in vehicles, such as passenger compartment lamps, map lamps, vanity-mirror lamps, door lamps, and trunk compartment lamps. In particular, the present invention relates to an automotive lamp unit and a method for manufacturing the same, in which a circuit for switching on automotive lamps by connecting the automotive lamps to a power source (battery) is formed with bus bars.
2. Description of the Related Art
Hitherto, a plurality of bus bars have been individually inserted in recesses formed in a resin base member, each bus bar serving as a wire, so that the bus bars are used as a circuit.
In the above-described known technology, a problem has been found in that since the known automotive lamp unit includes a plurality of bus bars, when, for example, four bus bars constitute a circuit, the four bus bars must be individually inserted in recesses of a base member, whereby manufacturing processes and working period are increased, thereby increasing manufacturing costs.
Another problem has been found in that when vibration is applied to the bus bars inserted in the recesses of the base member, there is a risk of the bus bars removing from the recesses and coming into contact with each other, thereby causing short circuits.
Accordingly, it is an object of the present invention to provide an automotive lamp unit and a method for manufacturing the same, in which manufacturing is performed in two major processes, that is, a plurality of bus bars are formed integrally with each other via bridge portions and the plurality of bus bars mounted on a base member are separated from each other at the bridge portions, thereby forming a circuit, whereby manufacturing costs can be reduced by improving efficiency in the manufacturing processes and reducing working period.
It is another object of the present invention to provide an automotive lamp unit and a method for manufacturing the same, in which bridge portions of a plurality of bus bars are bent so as to come into contact with inner faces of small holes formed in a base member, whereby each bus bar is fixed to the base member by a fixing member such as recesses and the small holes, thereby preventing the bus bars from removing from the base member by vibration.
To these ends, according to an aspect of the present invention, an automotive lamp unit comprises a bus bar unit forming a circuit with a plurality of bus bars connected with each other via a bridge portion, the bus bar unit including terminals, for connection to switches and to a power source, and a supporting member for supporting a lamp, the circuit serving to switch on the lamp; and a resin base member provided with the bus bar unit mounted thereon at a predetermined position thereof, a small hole being formed in the resin base member at a position thereof associated with the bridge portion. The plurality of bus bars are separated from each other at the bridge portion which is disposed in the small hole.
In the automotive lamp unit, cut-and-raised parts of the plurality of bus bars separated from each other at the bridge portion disposed in the small hole may be in contact with an edge of the small hole. The bridge portion may be formed so as to have a reduced width, thereby facilitating separation of the plurality of bus bars from each other, or may be provided with a groove for cutting and raising thereat so that the bridge portion has a reduced thickness, whereby the bridge portion is easily cut and raised.
According to another aspect of the present invention, a method for manufacturing an automotive lamp unit comprises the steps of mounting at least one part of a bus bar unit including a plurality of bus bars integrated with each other via a bridge portion on a base member made of a molded resin at a predetermined position of the base member; and separating the plurality of bus bars at the bridge portion by pressing, the bridge portion being disposed in a small hole formed in the base member at a position opposing a rear face of the bridge portion. In the method, cut-and-raised parts of the plurality of bus bars separated from each other at the bridge portion disposed in the small hole may be brought into contact with an edge of the small hole by pressing.